HP35s RPN Series # 3 [ENTER]

[MarkHaysHarris777]

(02-18-2015 11:37 PM)Sanjeev Visvanatha Wrote:  

(02-18-2015 08:24 PM)MarkHaysHarris777 Wrote:  What makes [ENTER] a conundrum?

[ENTER] causes confusion because its called 'ENTER' and because it really doesn't enter anything.

It enters the X register value into the Y register. I have always thought of it as "STO Y". This is what it does in its simplest sense. The named function of STOring to a stack register did not exist at the time the earliest HP RPN machines came out.

Yes, many think of it that way (which is kinda my point)... that is NOT what it does. The [ENTER] key initiates 'stack lift' (which is way more baggage than STO Y. The T reg is lost, Z is copied into T, Y is copied into Z, and X is replicated (copied) into Y; automated stack lift is canceled (for the next keying) and the X keying is terminated. whew. Goes a lot further than, STO Y. Of course moderns want an input buffer, and they want the [ENTER] key to STO X basically (leaving the stack alone). I am not in favor of this, actually. I configure my Droid virtual RPN calc (RealCalc) to use a traditional [ENTER] and XYZT four level stack.

Cheers,
marcus